A：赤道
B：0°和180°
C：20°W和160°E
D：20°E和160°W
制作人体口腔上皮细胞临时装片时，漱口的液体、载玻片上滴加的液体、染色用的液体分别是（ ）
写出3个带“天”字的成语。____。
—The man at the gate _______ be our headmaster. He is always standing there every morning.
—No, it _______ be him. He is holding a meeting in the office now.
